sys = tf([1],[1 0.4 0]);
%p = bodeoptions('cstprefs');
%p.FreqUnits = 'Hz';
%p.FreqScale = 'Linear';
%h = bodeplot(sys,p);
w = logspace(-2,1,20);
%Compute the magnitude and phase of the frequency response of a SISO system.
[mag,phase,wout] = bode(sys);
mag1 = reshape(mag,[1,48]);
plot(wout,mag1);
hold on
phase1 = reshape(phase,[1,48]);
plot(wout,phase1);
hold on
w1 = [0.1*pi 0.4*pi 0.8*pi pi 2*pi];
A = [6.1427 0.60 0.16 0.1004 0.04];
Phai = [-126 -161.50 -169.34 -171 -183.60];
plot(w1,A,'o');
hold on
plot(w1,Phai,'o');